1. Introduction

Debian GNU/Linux
(http://www.debian.org)
is the premier volunteer-supported Linux distribution.
Unfortunately, setting up printers in Debian can be difficult. Also,
simple step-by-step instructions for sharing printers between Windows
and Linux using the latest tools are hard to find. This HOWTO was
written to address both problems.

This HOWTO will demonstrate how to use command-line tools to configure your
Debian system for printing. It will explain how to send documents
from Linux to Windows printers and how to share Linux printers with
Windows PCs. Some troubleshooting examples are also given.

2. Getting Started

2.1. Linux Printing Components

The Common UNIX Printing System
(http://www.cups.org)
is a print spooler and a set
of support programs for using and administering printers.

Samba

Samba
(http://www.samba.org)
is software that allows non-Windows computers to act
like Windows computers on a network by implementing Windows file
and printer sharing protocols.

Printer Drivers

LinuxPrinting.org
(http://www.linuxprinting.org)
offers the largest number of printer drivers
and maintains a database of printers supported under Linux. You must
download a printer driver for each model of printer you want to use
in Linux. A printer driver consists of a PPD file and a filter
program, or only a PPD file for PostScript printers.

2.2. Required Packages

All of the required programs and libraries are part of the standard
Debian archive. You may download and install these packages with the
usual Debian packaging tools. The following is a list of packages
you need:

Additional packages may be required for specific printers. For example,
the hpijs package must be installed for many HP InkJet,
DeskJet and LaserJet printers to function properly. The PPD files for these
printers are identified by the string hpijs in their
filenames.

2.3. CUPS Local Printer Configuration

The lpadmin command is used to configure printers. The
following is an example of setting up a laser printer with CUPS.
You will have to become root or use sudo to execute these commands:

Please note that bash has a builtin command called
enable, so bash users must use the full path
(/usr/bin/enable) to enable printers.

The first command creates a new printer called "Laser"
that is connected to the first parallel port and is using the PPD
file /root/laser.ppd.
"Laser" is then enabled and told to accept jobs with
the enable and accept commands.
The last command sets "Laser" as the default printer.

If your printer is connected to a USB port or if you do not know the
correct device-uri for your printer try running
/usr/sbin/lpinfo -v to get a list of available
printer devices.

Make sure your printer's page size and other options are set correctly
by running /usr/bin/lpoptions -l.
More detailed information about printer configuration
is available in the CUPS documentation.

2.4. Linux Printing Basics

Figure 1. Printing Locally

Documents are spooled by using either lpr or
lp followed
by the file name. You may view the printer queue and check the printer
status with the command lpstat -o or
lpstat -p. To cancel a print job use either
cancel or lprm followed by the job id.

The CUPS spooler daemon is called cupsd.
It converts documents
to PostScript, then converts them to a format native to the printer
Figure 1. Printers that do not understand PostScript
use a rasterized, or bitmap, format for documents. Rasterized formats
can be much larger than the original PostScript, and will take longer
to send to the printer.

Filters are programs used to convert documents from one format to
another. The CUPS spooler will do its best to find a suitable filter
for the documents you send. If no filter suitable for converting your
document is installed you will receive an error similar to lpr:
unable to print file: client-error-document-format-not-supported.

Many applications do not include filters for their documents formats.
Documents created with these applications can only be printed from
within the application itself, unless the document is exported to
PostScript or another standard format.

3. Printing To Windows PCs

3.1. Connecting To Windows

Figure 2. Network Printing

SMB and CIFS are the Windows file and printer sharing protocols.
We use Samba to speak to the Windows PCs using these protocols. Before
configuring CUPS we should make sure we can connect to the Windows
PC with smbclient, the Samba SMB/CIFS client
Figure 2.

As mentioned above, bash has a builtin command called
enable, so bash users must use the full path
(/usr/bin/enable) to enable printers.

The "lpadmin" command sets up a the shared Windows printer by
giving the username, password, netbios name and printer name as a single
parameter.
See Section 2.3 for a further explanation of the commands
above.

Your printer is now ready to test. Send a file to the printer with
the lp command followed by a filename, or
by printing a document from within an application.

You will need to download and install Windows printer drivers for
each Linux printer you are sharing. Windows printer drivers can be
found by searching the web site of your printer manufacturer.

4.2. Samba Configuration

If you are allowing anonymous access to your printer you will need
to create a user account for remote print jobs:

/usr/sbin/adduser --system --disabled-password smbprint

This command adds a user called "smbprint" to your system. Make
sure there is enough disk space in /home/smbprint, the
"smbprint" user's home directory, to spool files. Check
that the "smbprint" user does not have permission on your
system to read or modify sensitive files and directories. If you have
configured CUPS to restrict printing to certain users on your system,
you must allow the "smbprint" user to access printers you
want to share.

The Samba configuration file is /etc/samba/smb.conf.
The following is an example configuration file set up to use CUPS with
the "smbprint" user:

Please note that this configuration will allow printing by anyone
that can make a network connection to your computer and is
not recommended for computers on untrusted networks, such as
computers with direct Internet connections. If you need to
implement access control, set security = user or
security = domain
and read the Samba man pages for further information.

Once you have added the above settings to your Samba configuration
file you must restart Samba with the command:

/etc/init.d/samba restart

4.3. CUPS Configuration

Windows printer drivers format their output for the printer before
sending it across the network. You must configure CUPS to accept
the pre-formatted output by uncommenting the following line from
/etc/cups/mime.convs:

application/octet-stream application/vnd.cups-raw 0 -

Also uncomment the following line from
/etc/cups/mime.types:

application/octet-stream

Now CUPS must be told to allow connections from other machines on
the network. Add these lines to /etc/cups/cupsd.conf:

<Location /printers>
AuthType None
Order Deny,Allow
Deny From None
Allow From All
</Location>

As in the Samba configuration, this configuration allows any computer
to connect to your printers and is not recommended for computers on
untrusted networks. For information about tightening access control
to your printers, see the cupsd.conf man page
and the CUPS documentation.

Finally, restart cups with the following command:

/etc/init.d/cupsys restart

Your Linux printers should now be shared to Windows PCs on the LAN.
Follow the usual steps for adding a network printer to your Windows
PCs, and remember to print a test page.

5. Troubleshooting

5.1. Failing To Connect To Windows Printers

When smbspool, the
smbclient utility CUPS uses,
fails to connect properly it emits error messages
that are humorous but not very helpful. One such message is Unable
to connect to SAMBA host: Success. Another sign of connection failures
is when documents seem to get stuck on the queue when printing to
Windows printers.

View the most recent entries in the CUPS log with the following command:

/usr/bin/tail /var/log/cups/error_log

If you see a message similar to cli_connect() failed... then
smbspool could not find the Windows PC you are
trying to connect to.
Check the spelling of the Windows PC's host name. Check that the
Windows PC is turned on and that its network connection is functioning
properly. Make sure you can connect to it using
smbclient as shown in Section 3.1.

If you see a message similar to SMB tree connect failed: ERRSRV
- ERRinvnetname then smbclient connected
to the Windows PC
but could not connect to the printer you requested. Check the spelling
of the shared printer using smbclient as shown in
Section 3.1.

5.2. Other Failures

Other failures include being unable to print to a local printer and
having your print jobs disappear from the queue without being printed.
You may also see vague error messages such as Child process 2384
exited with status 32.

Increase CUPS' logging level to "debug" to see more messages about
what happened before the print job failed.

Open the main CUPS configuration file /etc/cups/cupsd.conf in
a text editor.

Change the line that reads "LogLevel warn" to "LogLevel debug".

Save the configuration file and exit the text editor.

Restart the CUPS server with the command:

/etc/init.d/cupsys restart

You can follow the CUPS log with the following command:

/usr/bin/tail -f /var/log/cups/error_log

You should see a line that reads Scheduler shutting down due to
SIGTERM. This indicates that the CUPS server was stopped successfully.

Send your print job again and watch for useful debug messages that
appear. One example of a useful debug message is GNU Ghostscript
7.05: Can't start ijs server 'hpijs'. In this case the solution
is to install the "hpijs" package.

If you cannot determine the cause of the failure, do an Internet search
for key terms in error messages you see; it is likely that someone
has solved your problem before. You may also try upgrading the packages
listed in Section 2.2 to their latest versions.

6. License

This manual is free software; you may redistribute it and/or modify it under
the terms of the GNU General Public License as published by the Free Software
Foundation; either version 2, or (at your option) any later version.

This is distributed in the hope that it will be useful, but without any
warranty; without even the implied warranty of merchantability or fitness for
a particular purpose. See the GNU General Public License for more details.

A copy of the GNU General Public License is available as
/usr/share/common-licenses/GPL in the Debian GNU/Linux distribution or on the
World Wide Web at http://www.gnu.org/copyleft/gpl.html. You can also obtain it
by writing to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
Boston, MA 02111-1307, USA.